38. Ten-Stranding
39. Curve showing relation between Pressures of Cordite and Black Powder,
by Professor Vivian Lewes
40. Marshall's Apparatus for Moisture in Cordite
41. Lunge's Nitrometer
42. Modified do.
43. Horn's Nitrometer
44. Schultze-Tieman Apparatus for Determination of Nitrogen in Gun-Cotton
45. Decomposition Flask for Schultze-Tieman Method
46. Abel's Heat Test Apparatus
47. Apparatus for Separation of Nitro-Glycerine from Dynamite
48. Test Tube arranged for Heat Test
49. Page's Regulator
50. Do. showing Bye-Pass and Cut-off Arrangement
51. Will's Apparatus
52 & 53. Curves obtained
54. Dynamite Mortar
55. Quinan's Pressure Gauge
56. Steel Punch and Lead Cylinder for Use with Pressure Gauge
57. Micrometer Calipers for Measuring Thickness of Lead Cylinders
58. Section of Lead Cylinders before and after Explosion
59. Noble's Pressure Gauge
60. Crusher Gauge

NITRO-EXPLOSIVES.

CHAPTER I.

_INTRODUCTORY._

The Nitro-Explosives--Substances that have been Nitrated--The Danger Area--
Systems of Professors Lodge, Zenger, and Melsens for the Protection of
Buildings from Lightning, &c.

The manufacture of the various nitro-explosives has made great advances
during late years, and the various forms of nitro-compounds are gradually
replacing the older forms of explosives, both for blasting purposes and
also for propulsive agents, under the form of smokeless powders. The
nitro-explosives belong to the so-called High Explosives, and may be
defined as any chemical compound possessed of explosive properties, or
capable of combining with metals to form an explosive compound, which is
produced by the chemical action of nitric acid, either alone or mixed with
sulphuric acid, upon any carbonaceous substance, whether such compound is
mechanically mixed with other substances or not.[A]

[Footnote A: Definition given in Order of Council, No. 1, Explosives Act,
1875.]

The number of compounds and mixtures included under this definition is
very large, and they are of very different chemical composition. Among the
substances that have been nitrated are:--Cellulose, under various forms,
e.g., cotton, lignin, &c.; glycerine, benzene, starch, jute, sugar,
phenol, wood, straw, and even such substances as treacle and horse-dung.
Some of these are not made upon the large scale, others are but little
used. Those of most importance are nitro-glycerine and nitro-cellulose.
The former enters into the